Amp for VR4SR


I am looking for an amp to run my VR4SR.
My music is mainly vocal, strings and classic.
Has anyone checked VAC AVATAR vs UNISON RESEARCH - PREFORMANCE ?
Second hand will be just fine.
Budget is up to $5K- $6K
Would like to also hear about SS amp and or combination of Preamp + power amp - as long as it was checked Specifically with the VR4SR.
Thank you
128x128takeone
Post removed 
To add something to the mix I am running my 4sr's with a 16 watt Art Audio Carissa with great results in a 15x17 room. It depends on how loud you want to play. I think the quality of the amp and its power supply are key. The speaker will repeat what you put into it. Best of luck.

Blessings, Bob
Thank you all.
Most of the audiophiles that I made contact with are sure of 2 "basic facts":
One - the VR4SR LOVE valve - as if they actually made for it.
Two - they do need power.

So it seems that I need to check and listen to either strong (and unfortunately expensive) valve amplification or the combination of a "gentle" solid state power amp(maybe Jeff Rowland? I wonder if pass labs will not be too "cold") with a valve pre-amp.

Using hybrid as an amp (with valve pre amp) sound very interesting although I must admit that I never heard about Moscode until this thread.
Post removed 
Since I am located about 10 hours flight from the US I assume that home trail will not be so simple to arrange....
and it seems there is no dealer around.